Script Loader: Add id attributes to script assets.

This commit adds a unique ID attribute to script loader generated <script> tags as well as related <script> tags for inline JavaScript, translations, or parameters.

This is a first step in adding support for lazy loading scripts and styles, but for now is only used to assist in debugging generated output.

Props dd32, spacedmonkey.
See #48654.

Built from https://develop.svn.wordpress.org/trunk@48295


git-svn-id: https://core.svn.wordpress.org/trunk@48064 1a063a9b-81f0-0310-95a4-ce76da25c4cd